Magnetic sensing device and magnetic sensing method

Abstract

A magnetic sensing device including a substrate having a supporting surface on which a first sensing area, a third sensing area, and a second sensing area are consecutively arranged in a direction of movement. The first, the second, and the third sensing areas are provided with a first midline, a second midline, and a third midline in the direction of movement, respectively. The first and second midlines are symmetrical with respect to the third midline. The first and second sensing areas are jointly configured to output a first output signal. The third sensing area is configured to output a second output signal. A phase difference between the first and second output signals is 90 degrees, and the first and second output signals are jointly configured to determine the distance or the speed or the angle of movement and the direction of movement of the relative motion.

What is claimed is: 
     
         1 . A magnetic sensing device, the magnetic sensing device having a relative motion relationship with an object in a direction of movement, the object having a magnetic field to be measured thereon, the magnetic sensing device configured to sense a distance or a speed or an angle of movement and the direction of movement of the relative motion, the magnetic sensing device comprising:
 a substrate having a supporting surface being parallel to the direction of movement on which a first sensing area, a third sensing area, and a second sensing area are consecutively arranged in the direction of movement, the first sensing area, the second sensing area, and the third sensing area respectively provided with a first midline, a second midline, and a third midline in the direction of movement, the first midline, the second midline, and the third midline respectively passing through midpoints of projection lengths of the first sensing area, the second sensing area, and the third sensing area in the direction of movement and being perpendicular to the direction of movement, and the first midline and the second midline being symmetrical with respect to the third midline;   wherein the first sensing area and the second sensing area are jointly configured to output a first output signal, the third sensing area is configured to output a second output signal, and a phase difference between the first output signal and the second output signal is 90 degrees, and the first output signal and the second output signal are jointly configured to determine the distance or the speed or the angle of movement and the direction of movement of the relative motion;   wherein each of the first sensing area and the second sensing area includes a first sensing cell, each of the first sensing cells has a midline in the direction of movement, the midline of the first sensing cell of the first sensing area coincides with the first midline of the first sensing area, and the midline of the first sensing cell of the second sensing area coincides with the second midline of the second sensing area, the two first sensing cells produce changes with equal numerical values and same directions for a same magnetic field to be measured, the two first sensing cells are connected in series into a half-bridge structure to form a first sensor, and a connection point between the two first sensing cells outputs a first sensing signal, the first sensing signal is configured to generate the first output signal.   
     
     
         2 . The magnetic sensing device according to  claim 1 , wherein each of the first sensing area, the second sensing area, and the third sensing area is regularly shaped and configured on the supporting surface, the first midline, the second midline, and the third midline are central axes of the first sensing area, the second sensing area, and the third sensing area, respectively, the first sensing area, and the second sensing area, and the third sensing area are symmetrical with respect to the first midline, the second midline, and the third midline, respectively. 
     
     
         3 . The magnetic sensing device according to  claim 1 , wherein the third sensing area includes a first sensing cell and a second sensing cell, each of the first sensing cell and the second sensing cell is provided with a midline in the direction of movement, which midlines coincide with the third midline of the third sensing area, the first sensing cell and the second sensing cell produce changes with equal numerical values and opposite directions for a same magnetic field to be measured, the first sensing cell and the second sensing cell are connected in series into a half-bridge structure to form a third sensor, a connection point between the first sensing cell and the second sensing cell outputs a third sensing signal, the third sensing signal is configured to generate the second output signal. 
     
     
         4 . The magnetic sensing device according to  claim 1 , wherein each of the first sensing area and the second sensing area includes a first sensing cell and a second sensing cell, each of the first sensing cells and the second sensing cells has a midline in the direction of movement, the midline of the first sensing cell of the first sensing area coincides with the midline of the second sensing cell of the first sensing area and the first midline of the first sensing area, the midline of the first sensing cell of the second sensing area coincides with the midline of the second sensing cell of the second sensing area and the second midline of the second sensing area, the two first sensing cells produce changes with equal numerical values and same directions for a same magnetic field to be measured, and the changes have equal numerical values and opposite directions with the changes produced by the two second sensing cells for the same magnetic field to be measured, the first sensing cell and the second sensing cell of the first sensing area are connected in series into a half-bridge structure to form a first sensor, a connection point between the first sensing cell and the second sensing cell of the first sensing area outputs a first sensing signal, the first sensing cell and the second sensing cell of the second sensing area are connected in series into a half-bridge structure to form a second sensor, a connection point between the first sensing cell and the second sensing cell of the second sensing area outputs a second sensing signal, and the first sensing signal and the second sensing signal are configured to generate the first output signal. 
     
     
         5 . The magnetic sensing device according to  claim 1 , wherein the third sensing area comprises a first sensing cell, a second sensing cell, a third sensing cell, and a fourth sensing cell, each of the first sensing cell, the second sensing cell, the third sensing cell, and the fourth sensing cell has a midline in the direction of movement which midlines coincide with a third midline of the third sensing area, the first sensing cell and the third sensing cell produce changes with equal numerical values and same directions for a same magnetic field to be measured, and the changes have equal numerical values and opposite directions with the changes produced by the second sensing cell and the fourth sensing cell for the same magnetic field to be measured, the first sensing cell and the second sensing cell are connected in series into a half-bridge structure, and a connection point between the first sensing cell and the second sensing cell outputs a third sensing signal, the third sensing cell and the fourth sensing cell are connected in series into a half-bridge structure, and a connection point between the third sensing cell and the fourth sensing cell outputs a fourth sensing signal, the two half-bridge structures are connected into a full-bridge structure to form a third sensor, the third sensing signal and the fourth sensing signal are configured to generate the second output signal, the first sensing cell, the second sensing cell, the third sensing cell, and the fourth sensing cell are randomly arranged on the third midline, optionally, the first sensing cell, the fourth sensing cell, the third sensing cell, and the second sensing cell are sequentially and consecutively arranged on the third midline. 
     
     
         6 . The magnetic sensing device according to  claim 1 , wherein each of the first sensing area and the second sensing area includes a first sensing cell and a second sensing cell, each of the first sensing cell and the second sensing cell has a midline in the direction of movement, the midline of the first sensing cell of the first sensing area coincides with the midline of the second sensing cell of the first sensing area and the first midline of the first sensing area, the midline of the first sensing cell of the second sensing area coincides with the midline of the second sensing cell of the second sensing area and the second midline of the second sensing area, the two first sensing cells produce changes with equal numerical values and same directions for a same magnetic field to be measured, and the changes have equal numerical values and same or opposite directions with the changes produced by the two second sensing cells for the same magnetic field to be measured, the first sensing cell of the first sensing area and the first sensing cell of the second sensing area are connected in series into a half-bridge structure to form a first sensor, a connection point between the first sensing cell of the first sensing area and the first sensing cell of the second sensing area outputs a first sensing signal, the second sensing cell of the first sensing area and the second sensing cell of the second sensing area are connected in series into a half-bridge structure to form a second sensor, a connection point between the second sensing cell of the first sensing area and the second sensing cell of the second sensing area outputs a second sensing signal, the first sensing signal and the second sensing signal are configured to generate the first output signal. 
     
     
         7 . The magnetic sensing device according to  claim 1 , wherein each of the first sensing area, the second sensing area, and/or the third sensing area comprises a plurality of sensing cells, each of the sensing cells has a midline in the direction of movement, the midlines of the sensing cells of the first sensing area coincide with the first midline of the first sensing area, and the sensing cells are consecutively arranged on the first midline, the midlines of the sensing cells of the second sensing area coincide with the second midline of the second sensing area, and the sensing cells are consecutively arranged on the second midline, a portion of the sensing cells of the first sensing area and the second sensing area are connected in series and/or in parallel, and finally all the sensing cells are connected into a half-bridge structure or a full-bridge structure for generating the first output signal, optionally, a portion of the sensing cells of the first sensing area and the second sensing area produce changes with equal numerical values and same directions for a same magnetic field to be measured, and the changes have equal numerical values and opposite directions with the changes produced by another portion of the sensing cells for the same magnetic field to be measured, the two portions of the sensing cells are alternate and arranged on the first midline and the second midline one-by-one and spaced from each other, a portion of the sensing cells of the third sensing area are connected in series and/or in parallel, and finally all sensing cells are connected into a half-bridge structure or a full-bridge structure for generating the second output signal, a portion of the sensing cells of the third sensing area produce changes with equal numerical values and same directions for a same magnetic field to be measured, and the changes have equal numerical values and opposite directions with the changes produced by another portion of the sensing cells for the same magnetic field to be measured, the two portions of the sensing cells are alternate and arranged on the third midline one-by-one and spaced from each other. 
     
     
         8 . The magnetic sensing apparatus according to  claim 1 , wherein the magnetic sensing device further comprises a first operational amplifier and a second operational amplifier, the first sensing area and the second sensing area are connected to the first operational amplifier, which outputs the first output signal, the third sensing area is connected to the second operational amplifier, which outputs the second output signal. 
     
     
         9 . The magnetic sensing device according to  claim 1 , wherein the first sensing area, the second sensing area, and the third sensing area consist of anisotropic magnetoresistive cells or giant magnetoresistive sensing cells or tunneling magnetoresistive cells or Hall sensing cells. 
     
     
         10 . A magnetic sensing method for determining a distance or a speed or an angle of movement and a direction of movement of a relative motion between a magnetic sensing device and an object, the magnetic sensing device and the object having a relative motion relationship along the direction of movement, the object having a magnetic field to be measured thereon, wherein the magnetic sensing device employs a magnetic sensing device, the magnetic sensing device having a relative motion relationship with an object in a direction of movement, the object having a magnetic field to be measured thereon, the magnetic sensing device configured to sense a distance or a speed or an angle of movement and the direction of movement of the relative motion, the magnetic sensing device comprising:
 a substrate having a supporting surface being parallel to the direction of movement on which a first sensing area, a third sensing area, and a second sensing area are consecutively arranged in the direction of movement, the first sensing area, the second sensing area, and the third sensing area respectively provided with a first midline, a second midline, and a third midline in the direction of movement, the first midline, the second midline, and the third midline respectively passing through midpoints of projection lengths of the first sensing area, the second sensing area, and the third sensing area in the direction of movement and being perpendicular to the direction of movement, and the first midline and the second midline being symmetrical with respect to the third midline;   wherein the first sensing area and the second sensing area are jointly configured to output a first output signal, the third sensing area is configured to output a second output signal, and a phase difference between the first output signal and the second output signal is 90 degrees, and the first output signal and the second output signal are jointly configured to determine the distance or the speed or the angle of movement and the direction of movement of the relative motion,   wherein each of the first sensing area and the second sensing area includes a first sensing cell, each of the first sensing cells has a midline in the direction of movement, the midline of the first sensing cell of the first sensing area coincides with the first midline of the first sensing area, and the midline of the first sensing cell of the second sensing area coincides with the second midline of the second sensing area, the two first sensing cells produce changes with equal numerical values and same directions for a same magnetic field to be measured, the two first sensing cells are connected in series into a half-bridge structure to form a first sensor, and a connection point between the two first sensing cells outputs a first sensing signal, the first sensing signal is configured to generate the first output signal;   and wherein the magnetic sensing method comprises:   acquiring a first output signal jointly by a first sensing area and a second sensing area, acquiring a second output signal by a third sensing area, wherein a phase difference between the first output signal and the second output signal is 90 degrees, and determining the distance or the speed or the angle of movement and the direction of movement of the relative motion according to the first output signal and the second output signal.